Replacing Failing and Aging Water Treatment Infrastructure Remains a Priority
Kaukauna Utilities (KU) is providing an update on its Water Treatment System Improvement Project (a project four years in the making) following higher-than-anticipated construction bids. The increases are being driven by rising costs of materials and labor along with additional infrastructure requirements. As a result, adjustments to the project budget and future water rates will be required.
KU remains committed to providing its customers high-quality and reliable water service in accordance with its mission and responsibility as a community owned utility.
Why Moving Forward Matters
The Main Water Treatment Plant, the core of KU’s water treatment system, has served the community for generations. Some critical components still in use today, including the filters, reservoirs and pumps, are anywhere from 65 to 125 years old. KU has extended their life through diligent overhauls, maintenance and repairs. It has been determined the equipment can no longer be sustained and must now be replaced. This new facility will be moved to a new location outside of the Fox River floodplain to comply with current regulatory standards.
Investment in the water system is required regardless of treatment method. At a minimum, replacing the existing infrastructure, with the same quality of water as today, will cost an estimated $25 million. As KU replaces this failing and aging infrastructure, there is an opportunity to solve long-standing water hardness issues before it is delivered to homes and businesses.
If KU were to replace the existing infrastructure with the same treatment method, customers would continue paying for water softener and water heater maintenance, salt, bottled/filtered water, and the wear and tear hard water causes on appliances and fixtures/faucets. By investing an additional $10 million in reverse osmosis, an enhanced water treatment method, KU can address those issues and position its water system for the long term.
These infrastructure investments must advance at this time to mitigate increasing risk to system reliability. Moving forward now strengthens resiliency and reliability by relocating the water treatment facility outside of the Fox River floodplain and adding backup power generation to ensure water pumping can continue even during power outages.
How This Impacts Your Household Costs
To move this project forward, KU is proposing an approximate $28 per month increase (for the typical residential water customer) associated with the water treatment project. The plan is to implement this as a two-step water rate adjustment in 2027 and 2028, subject to final approval by the Public Service Commission of Wisconsin (PSC). A rate increase before the project is completed is necessary because many project costs occur during construction, and rates must be adjusted during that time to help cover those costs and meet regulatory financial requirements.
The increase reflects higher-than-anticipated construction bids, continued escalation in materials and labor costs, and the identification of additional infrastructure components necessary to ensure the new facilities operate safely and reliably for decades to come.
To better understand what this means for customers, it is helpful to look at two different cost comparisons, as shown in the chart below.
- Replacing the Main Water Treatment Plant is necessary due to its failing condition and age. The projected cost increase between using the current treatment method and incorporating reverse osmosis treatment is less than $12 per month on the typical residential bill.
- When comparing current water bills to projected bills after the new plant and reverse osmosis system are fully operational, typical residential customers would pay approximately $28 more per month on their water bill than they do today. This increase in cost may be offset by no longer having the need to operate a water softener, buy salt, and purchase bottled/filtered water because the water produced by the reverse osmosis system will be of similar quality to bottled water.
While reverse osmosis will increase monthly water bills, it was important for KU to consider the full household cost of water (not just the monthly water bill) when making this decision to proceed with the new water treatment system.
According to KU’s 2024 customer and plumber surveys:
- Residential customers incur an average cost of $17.64 per month on softener salt.
- Residential customers incur an average cost of $19.45 per month on bottled water or filtration systems.
- These numbers do not include appliance, water softener and water heater replacement costs, which are approximately $15-$20 per month for the typical residential customer. Reverse osmosis eliminates the hard water that shortens the lifespan of appliances and, therefore, reduces these costs for customers.
In total, households currently spend between $55-$75 per month on costs related to hard water. Eliminating the need for a water softener would remove ongoing expenses such as salt, water softener and water heater maintenance and replacement, bottled/filtered water, and much of the appliance and fixture/faucet wear caused by hard water. When those avoided costs are considered, many households and businesses will see lower overall water-related expenses — even with a higher base water bill.
Looking Ahead
KU understands that rate increases are challenging for customers and remains committed to transparency and thoughtful implementation as the project moves forward. The utility will continue working directly with customers to provide information and connect customers with available assistance resources where possible.
“This is not a decision we take lightly,” said KU General Manager, Michael Avanzi. “We know this represents a significant investment for our customers. Our responsibility is to ensure that Kaukauna has a high-quality and reliable water system not just today, but for the future of our community. Replacing this failing and aging infrastructure and investing in reverse osmosis now allows us to solve long-standing water quality concerns and build a system our community can depend on for generations to come.”
Due to the increase in project costs, KU has filed a notification of cost increase to the PSC, in accordance with the Certificate of Authority issued in May 2025. While the utility awaits final review of the notification, the Kaukauna Utilities Commission has granted approval to award the construction contract to Mid City Corporation. Once under contract, KU will work diligently with Mid City to reduce project costs wherever possible.
As part of this regulatory review process, KU will delay groundbreaking activities until PSC approval has been issued. The review process will likely affect the construction timeline. However, KU remains in contact with the PSC and other regulatory agencies to help minimize potential delays.
KU will continue providing updates as the project moves forward and encourages customers to review the supporting materials available on the KU website – https://www.kaukaunautilities.com/reverseosmosis/.
For questions related to the water treatment project, contact Water Superintendent, Andy Vanden Heuvel, at 920-858-9180.
